Liu Zhixiong, El-Demellawi Jehad K, Bakr Osman M, Ooi Boon S, Alshareef Husam N
Materials Science and Engineering, Physical Science and Engineering (PSE) Division, King Abdullah University of Science and Technology, Thuwal 23955-6900, Kingdom of Saudi Arabia.
Photonics Laboratory, Computer, Electrical and Mathematical Sciences and Engineering (CEMSE) Division, King Abdullah University of Science and Technology (KAUST), Thuwal 21534, Saudi Arabia.
ACS Nano. 2022 May 24;16(5):7904-7914. doi: 10.1021/acsnano.2c00558. Epub 2022 May 1.
The ability of MXenes to efficiently absorb light is greatly enriched by the surface plasmons oscillating at their two-dimensional (2D) surfaces. Thus far, MXenes have shown impressive plasmonic absorptions spanning the visible and infrared (IR) regimes. However, their potential use in IR optoelectronic applications, including photodiodes, has been marginally investigated. Besides, their relatively low resistivity has limited their use as photosensing materials due to their intrinsic high dark current. Herein, heterostructures made of methylammonium lead triiodide (MAPbI) perovskite and niobium carbide (NbC) MXene are prepared with a matching band structure and exploited for self-powered visible-near IR (NIR) photodiodes. Using MAPbI has expanded the operation range of the MAPbI/NbC photodiode to the visible regime while suppressing the relatively large dark current of the NIR-absorbing NbC. In consequence, the fabricated MAPbI/NbC photodiode has responded linearly to white light illumination with a responsivity of 0.25 A/W and a temporal photoresponse of <4.5 μs. Furthermore, when illuminated by NIR laser (1064 nm), our photodiode demonstrates a higher on/off ratio (∼10) and faster response times (<30 ms) compared to that of planar NbC-only detectors (<2 and 20 s, respectively). The performed space-charge-limited current (SCLC) and capacitance measurements reveal that such an efficient and enhanced charge transfer depends on the coordinate bonding between the surface groups of the MXene and the undercoordinated Pb ions of the MAPbI at the passivated MAPbI/NbC interface.
二维(2D)表面振荡的表面等离子体激元极大地增强了MXenes高效吸收光的能力。到目前为止,MXenes在可见光和红外(IR)波段均表现出令人印象深刻的等离子体吸收特性。然而,它们在包括光电二极管在内的红外光电子应用中的潜在用途研究较少。此外,由于其固有的高暗电流,相对较低的电阻率限制了它们作为光传感材料的应用。在此,制备了具有匹配能带结构的由甲基碘化铅(MAPbI)钙钛矿和碳化铌(NbC)MXene组成的异质结构,并将其用于自供电可见光-近红外(NIR)光电二极管。使用MAPbI将MAPbI/NbC光电二极管的工作范围扩展到可见光波段,同时抑制了吸收近红外光的NbC相对较大的暗电流。结果,制备的MAPbI/NbC光电二极管对白光照明呈线性响应,响应度为0.25 A/W,时间光响应小于4.5 μs。此外,与仅平面NbC探测器相比(分别为<2和20 s),当用近红外激光(1064 nm)照射时,我们的光电二极管显示出更高的开/关比(~10)和更快的响应时间(<30 ms)。进行的空间电荷限制电流(SCLC)和电容测量表明,这种高效且增强的电荷转移取决于MXene表面基团与钝化的MAPbI/NbC界面处MAPbI配位不足的Pb离子之间的配位键。